22 



BULLETIN 335, U. S. DEPARTMENT OP AGBICULTTJEE. 



cream of tartar was recovered, so far as this could be accomplished 

 in water solution. These data are presented in a subsequent section 

 of this paper. 



Table 4. — Increase of sugar and decrease of acid for certain periods, 1912. 

 i 



[Results in grams per 100 cc] 



SANDUSKY, OHIO. 



Date. 



Concord: 

 Sept. 4. 

 Oct. 16. 



Catawba: 

 Sept. 17 

 Nov. 4. 



Delaware: 



Aug. 2. 



Aug. 30. 

 Concord: 



Aug. 2. 



Aug. 30. 



Condition of berries. 



Nearly all colored . 

 Fully ripe 



Partly colored . 

 Not fully ripe. 



Days 

 elapsed. 



Total 

 sugar. 



8.60 

 15.92 



10.38 

 16.77 



Gain of 

 sugar. 



} 7.32 

 | 6.39 



Total 

 acid. 



/ 1.91 



\ .95 



/ 2.12 



\ 1.28 



Loss of 

 acid. 



0.96 



Ratio loss 

 of acid 

 to gain 



of sugar. 



1:7.6 

 1:7.6 



Acid-su- 

 gar ratio 

 in ripe 

 fruit. 



1:16.7 

 1:13 



CHARLOTTESVILLE, VA. 



60 per cent colored. 

 Fully ripe 



60 per cent colored. 

 Fully ripe 



2S 



13.08 



25.78 



5.16 

 15.21 



| 12. ', 



10.05 



1.92 



{•♦ 



46 



1.23 



}'•' 



1: 37.3 



1:19 



COMPOSITION OF THE WHOLE FRUIT. 



A portion of each fruit sample used for the juice analysis in 1912 

 was taken to make a fairly complete analysis of the whole fruit used 

 for the acid-sugar investigation. The method followed in taking and 

 handling the samples for this work has been given with sufficient 

 detail under "Sources and preparation of samples." 



The apparent irregularity in the increased content of cream of 

 tartar as the fruit matured and the fact that crystals of this salt 

 are deposited in the fruit during ripening first suggested the com- 

 plete exhaustion of the organic salts from the berries. Then the 

 further considerations as to whether the total weight of acid present 

 in the fruit really decreased during ripening or was simply reduced 

 in percentage by reason of the influx of sap and by the formation 

 of sugar in the fruit was a point requiring investigation. This latter 

 question was suggested by some critical discussion of the results 

 obtained in 1911, during which it was pointed out by colleagues in 

 the Bureau of Chemistry that it had not been definitely shown that 

 acid was eliminated during ripening, though this appeared from 

 the results to be the case. This discussion led the authors to include 

 in the work for 1912 determination of the volume in cubic centi- 

 meters, the specific gravity, and the exact weight in grams, of 100 

 berries from the composite sample taken for the juice analysis. 

 There was also concluded a fairly complete ash analysis of a portion 



